The hcall H_GET_PERF_COUNTER_INFO with counter request value as
PROCESSOR_CONFIG(0X90), can be used to get the system
processor configuration information. To expose the system
processor config information, patch adds sysfs file called
"processor_config" to the "/sys/devices/hv_gpci/interface/"
of hv_gpci pmu driver.

Add macro for PROCESSOR_CONFIG counter request value in hv-gpci.h file.
Also add a new function called "sysinfo_device_attr_create",
which will create and add required device attribute to the
interface_attrs array.

The processor_config sysfs file is only available for power10
and above platforms. Add a new macro called
INTERFACE_PROCESSOR_CONFIG_ATTR, which points to the index of
NULL placefolder, for processor_config attribute in the interface_attrs
array. Also add macro INTERFACE_NULL_ATTR which points to index of NULL
attribute in interface_attrs array.

Signed-off-by: Kajol Jain <kj...@linux.ibm.com>
---
 arch/powerpc/perf/hv-gpci.c | 110 +++++++++++++++++++++++++++++++++---
 arch/powerpc/perf/hv-gpci.h |   5 +-
 2 files changed, 107 insertions(+), 8 deletions(-)

diff --git a/arch/powerpc/perf/hv-gpci.c b/arch/powerpc/perf/hv-gpci.c
index bca24725699e..c9fe74373e5f 100644
--- a/arch/powerpc/perf/hv-gpci.c
+++ b/arch/powerpc/perf/hv-gpci.c
@@ -237,6 +237,72 @@ static ssize_t processor_bus_topology_show(struct device 
*dev, struct device_att
        return ret;
 }
 
+static ssize_t processor_config_show(struct device *dev, struct 
device_attribute *attr,
+                                       char *buf)
+{
+       struct hv_gpci_request_buffer *arg;
+       unsigned long ret;
+       size_t n = 0;
+
+       arg = (void *)get_cpu_var(hv_gpci_reqb);
+       memset(arg, 0, HGPCI_REQ_BUFFER_SIZE);
+
+       /*
+        * Pass the counter request value 0x90 corresponds to request
+        * type 'Processor_config', to retrieve
+        * the system processor information.
+        * starting_index value implies the starting hardware
+        * processor index.
+        */
+       ret = systeminfo_gpci_request(PROCESSOR_CONFIG, 0, 0, buf, &n, arg);
+
+       if (!ret)
+               return n;
+
+       if (ret != H_PARAMETER)
+               goto out;
+
+       /*
+        * ret value as 'H_PARAMETER' corresponds to 'GEN_BUF_TOO_SMALL', which
+        * implies that buffer can't accommodate all information, and a partial 
buffer
+        * returned. To handle that, we need to take subsequent requests
+        * with next starting index to retrieve additional (missing) data.
+        * Below loop do subsequent hcalls with next starting index and add it
+        * to buffer util we get all the information.
+        */
+       while (ret == H_PARAMETER) {
+               int returned_values = be16_to_cpu(arg->params.returned_values);
+               int elementsize = be16_to_cpu(arg->params.cv_element_size);
+               int last_element = (returned_values - 1) * elementsize;
+
+               /*
+                * Since the starting index is part of counter_value
+                * buffer elements, use the starting index value in the last
+                * element and add 1 to subsequent hcalls.
+                */
+               u32 starting_index = arg->bytes[last_element + 3] +
+                               (arg->bytes[last_element + 2] << 8) +
+                               (arg->bytes[last_element + 1] << 16) +
+                               (arg->bytes[last_element] << 24) + 1;
+
+               memset(arg, 0, HGPCI_REQ_BUFFER_SIZE);
+
+               ret = systeminfo_gpci_request(PROCESSOR_CONFIG, starting_index, 
0, buf, &n, arg);
+
+               if (!ret)
+                       return n;
+
+               if (ret != H_PARAMETER)
+                       goto out;
+       }
+
+       return n;
+
+out:
+       put_cpu_var(hv_gpci_reqb);
+       return ret;
+}
+
 static DEVICE_ATTR_RO(kernel_version);
 static DEVICE_ATTR_RO(cpumask);
 
@@ -258,6 +324,11 @@ static struct attribute *interface_attrs[] = {
         * attribute, set in init function if applicable.
         */
        NULL,
+       /*
+        * This NULL is a placeholder for the processor_config
+        * attribute, set in init function if applicable.
+        */
+       NULL,
        NULL,
 };
 
@@ -463,21 +534,46 @@ static int hv_gpci_cpu_hotplug_init(void)
                          ppc_hv_gpci_cpu_offline);
 }
 
-static void add_sysinfo_interface_files(void)
+static void sysinfo_device_attr_create(int sysinfo_interface_group_index)
 {
-       struct device_attribute *attr = kzalloc(sizeof(*attr), GFP_KERNEL);
+       struct device_attribute *attr;
 
+       if (sysinfo_interface_group_index < 
INTERFACE_PROCESSOR_BUS_TOPOLOGY_ATTR ||
+                       sysinfo_interface_group_index >= INTERFACE_NULL_ATTR) {
+               pr_info("Wrong interface group index for system information\n");
+               return;
+       }
+
+       attr = kzalloc(sizeof(*attr), GFP_KERNEL);
        if (!attr) {
-               pr_info("Memory allocation failed for processor_bug_topology 
interface file\n");
+               pr_info("Mem allocation failed, sysinfo index:%d\n", 
sysinfo_interface_group_index);
                return;
        }
 
-       /* Add processor_bus_topology attribute in the interface_attrs 
attribute array */
        sysfs_attr_init(&attr->attr);
-       attr->attr.name = "processor_bug_topology";
+
+       switch (sysinfo_interface_group_index) {
+       case INTERFACE_PROCESSOR_BUS_TOPOLOGY_ATTR:
+               attr->attr.name = "processor_bug_topology";
+               attr->show = processor_bus_topology_show;
+       break;
+       case INTERFACE_PROCESSOR_CONFIG_ATTR:
+               attr->attr.name = "processor_config";
+               attr->show = processor_config_show;
+       break;
+       }
+
        attr->attr.mode = 0444;
-       attr->show = processor_bus_topology_show;
-       interface_attrs[INTERFACE_PROCESSOR_BUS_TOPOLOGY_ATTR] = &attr->attr;
+       interface_attrs[sysinfo_interface_group_index] = &attr->attr;
+}
+
+static void add_sysinfo_interface_files(void)
+{
+       /* Add processor_bus_topology attribute in the interface_attrs 
attribute array */
+       sysinfo_device_attr_create(INTERFACE_PROCESSOR_BUS_TOPOLOGY_ATTR);
+
+       /* Add processor_config attribute in the interface_attrs attribute 
array */
+       sysinfo_device_attr_create(INTERFACE_PROCESSOR_CONFIG_ATTR);
 }
 
 static int hv_gpci_init(void)
diff --git a/arch/powerpc/perf/hv-gpci.h b/arch/powerpc/perf/hv-gpci.h
index ff76bc010823..0d324a7c684b 100644
--- a/arch/powerpc/perf/hv-gpci.h
+++ b/arch/powerpc/perf/hv-gpci.h
@@ -24,10 +24,13 @@ enum {
 };
 
 /* Counter request value to retrieve system information */
-#define PROCESSOR_BUS_TOPOLOGY 0XD0
+#define PROCESSOR_BUS_TOPOLOGY 0XD0
+#define PROCESSOR_CONFIG       0X90
 
 /* Interface attribute array index to store system information */
 #define INTERFACE_PROCESSOR_BUS_TOPOLOGY_ATTR  6
+#define INTERFACE_PROCESSOR_CONFIG_ATTR                7
+#define INTERFACE_NULL_ATTR                    8
 
 #define REQUEST_FILE "../hv-gpci-requests.h"
 #define NAME_LOWER hv_gpci
-- 
2.35.3

Reply via email to